//  Operator.java
//
//  Authors:
//       Antonio J. Nebro <antonio@lcc.uma.es>
//       Juan J. Durillo <durillo@lcc.uma.es>
// 
//  Copyright (c) 2011 Antonio J. Nebro, Juan J. Durillo
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Lesser General Public License for more details.
// 
//  You should have received a copy of the GNU Lesser General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
package sg.atom.utils.algorithm.core;

import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;
import sg.atom.utils.algorithm.exceptions.AlgorithmException;

/**
 * Class representing an operator
 */
public abstract class Operator implements Serializable {

    /**
     * Stores the current operator parameters. It is defined as a Map of pairs
     * <<code>String</code>,
     * <code>Object</code>>, and it allow objects to be accessed by their names,
     * which are specified by the string.
     */
    protected final Map<String, Object> parameters_;

    /**
     * Constructor.
     */
    public Operator(HashMap<String, Object> parameters) {
        parameters_ = parameters;
    } // Operator

    /**
     * Abstract method that must be defined by all the operators. When invoked,
     * this method executes the operator represented by the current object.
     *
     * @param object This param inherits from Object to allow different kinds of
     * parameters for each operator. For example, a selection operator typically
     * receives a <code>SolutionSet</code> as a parameter, while a mutation
     * operator receives a <code>Solution</code>.
     * @return An object reference. The returned value depends on the operator.
     */
    abstract public Object execute(Object object) throws AlgorithmException;

    /**
     * Sets a new
     * <code>Object</code> parameter to the operator.
     *
     * @param name The parameter name.
     * @param value Object representing the parameter.
     */
    public void setParameter(String name, Object value) {
        parameters_.put(name, value);
    } // setParameter

    /**
     * Returns an object representing a parameter of the
     * <code>Operator</code>
     *
     * @param name The parameter name.
     * @return the parameter.
     */
    public Object getParameter(String name) {
        return parameters_.get(name);
    } //getParameter  
} // Operator
